Art of recovering light oils.



R. B. PAKEH.

'ART 0F BECOVERING LIGHT OILS.

APPLICATION FILED'MAR. 6| |916.

l ,252,481 l Patented Jan. 8, 1918.

RICHARD B. PARKER, 0F SOIVAY, NEW lYORK, ASSIGNOR TO SEMET-SOLVAY COMPANY, OF SOLVAY, NEW YORK, A CORPORATION OF NEW YORK.

ART OF RECOVERING LIGHT OILS.

Specification of Letters Patent. Y

Patented aan. s, regis.

Application led March 6, 1916. Serial No. 82,349.

which are present primarily as vapors in the' gases given ofi' in the destructive distillation of coal, as in the operation of by-prodl uct retort coke ovens.

In the process of recovering such oils, as heretofore practised, the mixed oil vapors are first collected by passing the as through and absorbing the oils in a suita le absorbent oil, as the so-called straw oil or other paraflin oil obtained in the distillation of petroleum, from which the oils, with cer tain accompanying impurities, are then distilled ofi' and the mixed distillate condensed and collected. This condensate is then distilled to separate the light oils proper, ben' zol, toluol and xylols, from each other and fromV the components of higher boiling point which would bel broken u by treatment with sulfuric acid, thus giving unrefined light oils.' p i Each of these is then washed with sulfurie acid to remove the unsaturated hydrocarbons and distilled to separate it from f' small proportions of components having other boiling points still remaining, to give pure products.

. In contrast with this practice, in my process, Whilethe light oils are collected from the gas in an absorbent oil and distilled ofi therefrom in the same manner as before, I treat the. mixed vapors as they come from 'the still in the first instance t'o separate therefromthose components of' higher boiling points, as olefins, &c., which Wouldbe broken up by treatment with sulfuric" acid and condense and collect together the remaining vapors. This mixed condensate is then Washed with sulfuric acid to remove `the unsaturated hydrocarbons and afterpoints, each of the light oils being recovered 1n a pure state.1

In this manner I am able to dispense entirely with one step of distillation, with consequent economy of operation, and morcovcr effect a considerable conservation of valuable product-Which has heretofore gone into the waste with the components having boiling points higher than the light oils.

My invention will be best understood by describing it in connection with the accompanying-drawing which illustrates in diagrammatic form a portion of the apparatus which may be used in carrying it into' effect.

Referring to the drawing, A indicates a still or column constructed in a well-known manner of superposed pans, into the upper part of which, as through a pipe, a, is admitted the absorbent oil, as straw oil, charged with the light oils to be recovered, and in which the light oils are distilled ol from the absorbent oil as by means of steam admitted at the bottom of the column through a pipe, b.

The vapors distilled o pass from the still, A, by pie d directly to a dephlegmating column, which is provided in its upper portion with cooling means, as a cooling coil, C While the residuum of absorbent oil is drawn oli through pipe c. In the column, B, the vapors are cooled to such an extent that those of highest boilingl points, including the olens, Snc., which would be broken up by treatment with sulfuric acidare condensed in the column and pass out at the bottom, by pipe e, to a collecting tank T. The uncondensed vapors, including the light oils, pass out at the top of the column, B, as by pipe, f, and are thereafter condensed and collected, as in a tank T2.

The mixed distillates in tank T2 are then Washed, as in a Washer W, first With' sulfurie acid to remove the unsaturated hydrocarbons present and afterward with an alkali, as a solution of caustic soda to remove any adherent acid. The Washed product is then drawn o", as to a tank, T3, While the Washing acid is separately drawn 0E as to tank T4. y f

The unsaturated hydrocarbons having thus been removed, the mixed condensates are distilled ini/any suitable 'or ywell-known mannerto separate the light oils from each other and from such components of higher boiling pointsgsuch as naphthalene, as may i be' present.

In this manner the li ht oils are recoveredas pure products 4with .ut a single distillation afterthey are driven off from the ab sorbent oil, With consequent economy of operation and completeness of recovery, the

advantages of which will be readily .understood by thoseskilled in the art.

' 'Having thus described my invention, what I claim as new and desire to secure by- Letters yPatent is 1.'The improvement in the art of '.recovering-,light oilsfrom gas which consists in absorbing the oil vapors of the gas in an absorbent oil, distilling off the'volatile components from the oil, condensing and separating from the more volatile components thoseof highest boiling points, including the oleins and the like, condensing together the remaining vapors and treating the ycondensate ,to remove vthe unsaturated Hydrocarbons and finally distillin oil' and separately recovermg the light o1 s.

2. The yimpro'ver'nent in the art-of recovfv ering light oils from gas which consists in absorbing thel oil vapors of the gas in an absorbing oil, distilling oli' the volatile components from the oil, separating by condenfsation from the more volatile components those of higher boiling points which would be broken up by treatment with sulfuric acid, condensing together the remaining by separating from the more volatile components those of highest boiling points, including theolens and the like, condensing together the remaining vapors, purifying the condensate by Washing with sulfuric acid and nallyseparating the purified product vfrom the acid.

InA testimony4 whereof I have hereunto subscribed my name this 29th day of February, A. D. 1916. I,

ARICI-IAII) B. PARKER. 

